A CPU is a Mii who is controlled by a computer. They appear in Wii Sports, Wii Sports Resort and Wii Sports Club games as the players the player must face. In games that require 2+ people, CPU Miis make a team. The better the skill level of the CPU is, the more skilled he/she is. Miis that are above 999 points are known as Pros.
In Wii Sports, there are 60 pre-made CPU Miis that can be your opponents: 30 boys and 30 girls. They appear as opponents in Tennis, Baseball and Boxing. In this last sport, not all girls appear. In Bowling, they can appear if you don't have enough Miis in your Mii Plaza or Mii Parade, playing in the other lanes.
In Wii Sports Resort, in addition to the 60 CPU Miis from Wii Sports, there are 40 new CPU Miis, 20 boys and 20 girls, making a total of 100 CPU Miis that can be your opponents. You play against them in Swordplay, Table Tennis - Match, Basketball - Pick-Up Game and Cycling. Again, they appear in Bowling, alongside your own Miis, no matter if you have enough Miis in your Mii Plaza or Mii Parade. They also appear as spectators in various sports, such as Table Tennis and Basketball,
In Wii Sports Club, 111 new CPU Miis replace the CPU Miis from Wii Sports Resort, sporting the full range of the Wii U's Mii Maker's updated feature set.
- CPUs from the Wii console appear to have been saved in the system's internal memory, but are hidden from the user's system. This may suggest why they disappear from audiences and other graphics if the player has more than 20 made Miis.
- CPUs are also promotional Miis, appearing in other games, several artwork and promotional images. They likely are assets from a central resource within Nintendo and not created specifically for Wii Sports.
- They aren't used in art for the 3DS game Tomodachi Life and subsequently, the mobile social app Miitomo. Those use their own set.
- The 3DS game Miitopia will auto assign townspeople roles with the Sports Club Miis if Spotpass is turned off.
- CPU Miis are not impossible to recreate, and can be made with good effort and a lot of time. However, the Wii U CPUs are harder to create than the Wii CPUs for obvious reasons.